/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/Transforms/TransformGizmoDataBinder.h
Broadcast whenever the tracked gizmo is changed (because one of multiple gizmos is dragged, or a new gizmo appears after no others are present).
typedef TMulticastDelegate_OneParam< void, [UCombinedTransformGizmo](API\Runtime\InteractiveToolsFramework\BaseGizmos\UCombinedTransformGizmo) * > FOnTrackedGizmoChanged